1. Technical Field
The present invention relates to a thin-film transistor (TFT), and more particularly, to a TFT substrate and a method of fabricating the TFT substrate.
2. Discussion of the Related Art
Liquid crystal displays (LCDs) are one of the most widely used types of flat panel displays. Generally, an LCD includes two substrates having electrodes and a liquid crystal layer interposed between the substrates. In an LCD, voltages are applied to electrodes to rearrange liquid crystal molecules of a liquid crystal layer, thereby controlling the amount of light that passes through the liquid crystal layer. As a result, a desired image is displayed on the LCD.
An LCD uses a thin-film transistor (TFT) substrate that includes a TFT for switching each pixel. A TFT substrate includes gate wiring which delivers a gate signal and data wiring which delivers a data signal. Copper, a metal having a low resistance, may be used for forming gate wiring and data wiring.
When gate wiring and data wiring are formed using copper, a semiconductor pattern may become contaminated during an etching process for forming the data wiring. In addition, contact characteristics between the data wiring and the semiconductor pattern may deteriorate. Accordingly, a separate layer may be formed to prevent contamination of the semiconductor pattern and to enhance contact characteristics of the semiconductor pattern. However, formation of the separate layer may require an additional mask process.